Isolation of Major Phenolic Compounds from the Extracts of Prunella L. Species Grown in Turkey and Their Antioxidant and Cytotoxic Activities

Abstract

The major phenolics of Prunella L. species were isolated, and antioxidant activites were determined by 2,2-azino-di-(3-ethylbenzothialozine-sulphonic acid). The isolated compounds were identified as rutin, rosmarinic acid and caffeic acid by high performance liquid chromatography-diode array detection. The results show that the phenolic compounds were isolated from Prunella L. species with high content ranged from 74% (Prunella grandiflora L.) to 99% (Prunella orientalis Bornm.), and the major compound of rosmarinic acid was isolated above 90% in all species. Antigrowth effects of Prunella L. species were tested against human breast cancer cell lines, MCF-7 (estrogen receptor-positive) and MDAMB-231 (estrogen receptor-negative) by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide) and ATP (adenosine triphosphate) viability assays. To determine the mode of cell death, M30-antigen assay was performed in order to measure apoptosis. It was found that Prunella laciniata (L.) L., P. orientalis Bornm. and P. grandiflora L. species showed antigrowth effect on MCF-7 and MDA-MB-231 breast cancer cells, but apoptosis was not observed. Practical Applications Four Prunella L. species (Prunella vulgaris L., Prunella laciniata L., Prunella grandiflora L. and Prunella orientalis Bornm.) have been used in Western and Chinese herbal medicine that possesses antioxidant properties. Prunella L. species have a broad chemical composition, consisting of bioactive molecules as phenolic acids, flavonoids and anthocyanidins. It was found that Prunella L. species showed a significant growth-inhibiting effect on human breast cancer cells, but apoptosis was not involved in cell death. The results suggest that the isolated rutin and rosmarinic acid, as the principal components of Prunella L. extracts, could be utilized as both medicine and herbal tea.